1. Field of the Invention
This invention relates to plasticized polyvinyl butyral (PVB) sheet containing dispersed heat absorbing additives and to a glass laminate containing such sheet.
2. Related Background Art
Laminated safety glass containing shock-dissipating sheet of plasticized PVB between two glass layers is widely used in vehicle and building windows where the PVB sheet functions to absorb the blow from the head of an occupant within a vehicle containing the window or from a foreign object from outside the window without penetrating the safety glass laminate. It is also known to disperse minor quantities of functional additives in the PVB sheet formulation to selectively absorb heat-producing infrared (IR) solar radiation while not hampering the transmission of visible light through the glass laminate containing such PVB sheet. With sheet containing such additives, excessive heating and physical damage to an interior area surrounded by the laminated glass (such as the interior of a vehicle parked in the sun) is thus avoided. In this regard, U.S. Pat. No. 5,830,568, discloses inorganic and organic IR-absorbing additives in PVB sheet in a layered safety glass laminate.
U.S. Pat. Nos. 5,405,962 and 5,986,099, disclose quaterrylenetetracarboxylic diimide compounds and their preparation. The ""962 patent discloses use of non-core substituted quaterrylene compounds as pigments or fluorescent dyes or as photoconductors. Uses for the core substituted diimide compounds of the ""099 patent are disclosed also as pigments or fluorescent dyes particularly for coloring organic materials or organic/inorganic composites.
A need continues to exist for improvements in the art of selectively controlling solar radiation in safety glass laminates by means of the composition of the PVB sheet in such laminates.
Now improvements have been made in the composition of PVB sheets containing additives for selectively controlling solar radiation.
Accordingly, a principal object of this invention is to provide IR-heat absorbing and visible light transmitting properties in glass laminates where heat blocking is achieved by the formulation of the PVB sheet per se without requiring additional functional layers in the laminate to accomplish this, i.e., on the surfaces of either the glass layer(s) or by incorporation of specially coated films within the laminate.
A specific object is to provide plasticized PVB sheet containing one or more organic IR-absorbing additives which can be combined with glass in a safety glass laminate to provide improved heat insulating properties.
Other objects will in part be obvious and will in part appear from the following description and claims.
These and other objects are accomplished by providing plasticized polyvinyl butyral sheet containing an infrared-absorbing effective amount of at least one quaterrylenetetracarboxylic diimide of formula I: 
wherein
R and Rxe2x80x2 are independently C1-C30-alkyl whose carbon chain optionally is interrupted by one or more of xe2x80x94Oxe2x80x94, xe2x80x94Sxe2x80x94, xe2x80x94NR1xe2x80x94, xe2x80x94COxe2x80x94 and/or xe2x80x94SO2xe2x80x94 and which optionally is monosubstituted or polysubstituted by cyano, C1-C6-alkoxy or a 5-, 6- or 7-membered heterocyclic radical which is attached via a nitrogen atom and which optionally contains additional heteroatoms and optionally is aromatic;
C5-C8-cycloalkyl whose carbon chain may be interrupted by one or more groups selected from the group consisting of xe2x80x94Oxe2x80x94, xe2x80x94Sxe2x80x94, xe2x80x94NR1xe2x80x94, xe2x80x94COxe2x80x94 and/or xe2x80x94SO2xe2x80x94 and which may be monosubstituted or polysubstituted by C1-C6-alkyl; or
aryl or hetaryl, each of which optionally is monosubstituted or polysubstituted by C1-C18-alkyl, C1-C6-alkoxy, cyano, xe2x80x94CONHR2, xe2x80x94NHCOR2 and/or aryl- or hetarylazo, each of which optionally is substituted by C1-C10-alkyl, C1-C6-alkoxy or halogen, where
R1 is hydrogen or C1-C6-alkyl; and
R2 is hydrogen; C1-C18-alkyl; aryl or hetaryl, each of which optionally is substituted by C1-C6-alkyl, C1-C6-alkoxy, halogen or cyano;
X is independently halogen; C1-C18-alkyl, aryloxy, arylthio, hetaryloxy or hetarylthio, each of which may be substituted by C1-C4-alkyl, or C1-C18-alkoxy; or 
where
R3 is C1-C8-alkyl, whose carbon chain may be interrupted by one or more groups selected from the group consisting of xe2x80x94Oxe2x80x94, xe2x80x94Sxe2x80x94, xe2x80x94NRxe2x80x94, xe2x80x94COxe2x80x94 and/or xe2x80x94SO2xe2x80x94 and which may be monosubstituted or polysubstituted by C1-C6-alkoxy or by a 5- to 7-membered heterocyclic radical which is attached via a nitrogen atom and may contain further heteroatoms and be aromatic; or
C5-C8-cycloalkyl whose carbon chain may be interrupted by one or more groups selected from the group consisting of xe2x80x94Oxe2x80x94, xe2x80x94Sxe2x80x94, xe2x80x94NR1xe2x80x94, xe2x80x94COxe2x80x94 and/or xe2x80x94SO2xe2x80x94 and which may be monosubstituted or polysubstituted by C1-C6-alkyl;
and p is from 0-16.
In a particularly preferred embodiment of the invention the quaterrylenetetracarboxylic diimide is a tert-alkylphenoxy-substituted quaterrylenetetracarboxylic diimide infrared-absorbing additive of formula II: 
where
Q is a N,Nxe2x80x2-disubstituted quaterrylene-3,4:13,14-tetracarboxylic diimide radical as described above;
R3 is the same as defined above;
Hal is chloro and/or bromo;
m is from 0 to 15; and
n is from 1 to 16, subject to the proviso that the sum m+n is xe2x89xa616.
The PVB sheet of this invention may also include one or more inorganic IR-absorbing additives such as nanoparticulate lanthanum hexaboride, antimony tin oxide, indium tin oxide and mixtures thereof. Colorants, e.g., pigments and dyes, UV stabilizers and adhesion control agents may also be included in the PVB sheet of this invention.
This invention is also directed to a laminate having two glass sheets with the above-described PVB sheet disposed therebetween. The laminate of this invention may also include two or more PVB sheets interposed between the glass sheets. For example, a laminate may have one PVB sheet containing an IR absorbing effective amount of quaterrylimide and a second PVB sheet containing one or more of an inorganic IR-absorbing additive. In addition, the laminates of this invention may include a functional PET film interposed between two sheets of PVB so long as the quaterrylimide present in either one PVB sheet alone or both PVB sheets together is an IR absorbing effective amount of quaterrylimide.